EIN EL-HILWEH, Lebanon (AP) _ At night, the alleyways of this usually raucous Palestinian refugee camp are deserted. People cower in their homes as gunmen loyal to Yasser Arafat and Abu Nidal stalk each other.

At least 19 people have been killed over the last five months in eye-for- an-eye gun and bomb attacks apparently touched off by Abu Nidal's opposition to the U.S.-sponsored Arab-Israeli peace talks in Washington.

Two years ago, 75 people were killed and 200 wounded in three days of fighting in Ein el-Hilweh, Lebanon's largest refugee camp, when Arafat's Fatah movement cracked down on Abu Nidal's Fatah-Revolutionary Council.

Before the latest spate of killings began in June, this teeming shantytown of about 60,000 people throbbed with life at night despite frequent gunplay by rival guerrilla factions.

Men in checkered kaffiyeh headdress crowded cafes to play cards and drink coffee. Fast-food spots sold sandwiches, drinks and cigarettes.

No more.

Khaled Zaatar, a 45-year-old baker and Arafat supporter who usually goes to work after midnight, stays home after dark.

''I feel someone's waiting at every corner with a pistol to kill me. It's just not safe,'' he says.

The bloodletting is adding to the pressure on Arafat, chairman of the Palestine Liberation Organization, to pull the Palestinian delegation out of the talks because Israel refuses to discuss an independent Palestinian state.

The PLO has no seat at the talks, but advises the Palestinian negotiators.

Arafat claims Iran and Saudi Arabia are financing Abu Nidal and other radical factions opposed to the peace talks.

So far, President Elias Hrawi's Syrian-backed government has made no move to send in troops to halt the violence. Until recently, most of the slayings were inside the camps and the Lebanese were not overly concerned.

But lately the bloodshed has spilled into Sidon, southern Lebanon's provincial capital, and other areas supposedly under government control.

Palestinian factions have tried in vain to mediate an end to the feud. They believe the Syrians and other Arab powers are using the conflict to settle old scores with Arafat.

Col. Munir Makdah, Fatah's militia commander in Lebanon, claims Abu Nidal receives ''at least $40 million from Iran and about $200 million from Saudi Arabia annually to paralyze the PLO.''

Iran opposes the peace talks. Its Lebanese surrogate, the Shiite Muslim Hezbollah, or Party of God, has intensified its attacks on Israel's so-called security zone in southern Lebanon.

This has triggered Israeli air raids and artillery bombardments recently that have killed or wounded scores of people.

Saudi Arabia supports peace negotiations but turned against Arafat in 1990 when he supported Saddam Hussein's invasion of Kuwait.

The Syrians, undisputed masters of Lebanon, are key players in the talks. They are not loathe, however, to put the squeeze on Israel during negotiations.

Syrian President Hafez Assad and Arafat have been jousting ever since Assad sponsored a PLO mutiny against Arafat in 1983 in a bid to control the Palestinian cause and so bolster his regional status.

Despite a recent drawing together, neither side trusts the other. Assad is not averse to undercutting Arafat when the opportunity arises.

Arafat and Abu Nidal - real name, Sabri al-Banna - have been at each other's throats since 1973, when Abu Nidal was expelled from Arafat's Fatah movement and sentenced to death in absentia.

He had tried to kill top aides of Arafat because he bitterly opposed PLO moves toward dialogue with Israel.

Since then, Abu Nidal has killed some of Arafat's most trusted lieutenants and carried out terrorist atrocities like the December 1985 attacks on Rome and Vienna airports, in which three terrorists were among 21 people slain.

The latest round of violence erupted June 8 when PLO security chief Atef Bseiso was assassinated in Paris. The PLO blamed Abu Nidal.

Col. Anwar Madi, Fatah's military commander in Lebanon, was killed in Sidon om June 30. Ten days later, Khalil Abu al-Hanna, a senior Abu Nidal lieutenant, was shot to death in the Bekaa Valley.